State amperes circuital law.show through an example,howthislawenablesaneasyevaluationofthemagneticfieldwhenthereisasymmetryinthesystem
.whatdoesatoroidconsistof?showthatforanidealtoroidofcloselywoundturns,themagneticfield-1insidethetoroidisconstantand2intheopenspaceinsideandexteriortothetoroidiszero.